Inertial sensing and magnetic field sensing are useful in a variety of different applications. Furthermore, inclusion of inertial sensing elements using micro electrical mechanical systems (MEMS) are continually finding new applications, e.g., attachments for video games and navigation systems to determine change of direction of the attachment. MEMS offer inexpensive solutions for these applications in a small package. Therefore, many MEMS-based inertial sensing elements can be used to increase sensitivity for determining directional acceleration of a moving object.
In the prior art it has been shown that using a seismic mass which includes a movable electrode that is arranged opposite to a fixed electrode can form a capacitor. Movement of the moveable electrode due to inertial forces resulting from an acceleration vector can result in changes in the capacitance. The change in the capacitance can be measured and correlated to the acceleration.
Similarly, various sensors are known that can correlate a perpendicular magnetic field to a change in electrical characteristics that can be measured to determine the magnitude of the magnetic field. However, the solutions provided in the prior art either lack the necessary sensitivity for effectively measuring magnetic fields that are parallel to the surface of a sensor or for measuring an acceleration vector that is perpendicular to the surface of the sensor.
A need exists to provide a MEMS-based sensor for effectively sensing magnetic fields that are tangential to the sensor and for sensing an acceleration vector that is perpendicular to the sensor.